Fixes mistake where GuiInspectorEntityGroup's onAdd doesn't explicitly return true, which can cause problems in some compilers.

Engine/source/gui/editor/inspector/entityGroup.cpp

@@ -41,6 +41,8 @@ bool GuiInspectorEntityGroup::onAdd()
 {
    if (!Parent::onAdd())
       return false;
+
+   return true;
 }
 
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